[3] It is endemic to Borneo and is known from both Malaysia (Sarawak, Sabah) and Indonesia (Kalimantan).

It is very similar to Chalcorana raniceps in colouration and general body shape but is clearly bigger in size.

[4] Chalcorana megalonesa occurs in tropical moist lowland and swamp forest at elevations of 20–600 m (66–1,969 ft) above sea level.

Breeding takes place in small, permanent ponds (usually >30 cm deep).

It can also be found in oil palm and forest concessions and appears to tolerate habitat disturbance.